Endotracheal tube with aerosol delivery apparatus II

ABSTRACT

Current methods of drug administration to the lungs are inefficient. ‘Endotracheal Tube with Aerosol Delivery Apparatus II’ is specifically designed for uniform intrapulmonary delivery of aerosolized medication in patients on mechanical ventilation. As opposed to the current methods of drug delivery where aerosol particles are generated at the proximal end of the ETT, with majority of the particles adhering to the endotracheal tube during delivery, this invention bypasses the endotracheal tube by generating aerosol particles at its distal end. This invention incorporates 1 to 6 (preferably 4 to 6) secondary cannulations in the wall of the ETT with pinhole terminal orifices at the distal tip of the ETT arranged symmetrically. The secondary cannulations continue proximally as semi-flexible tubules that terminate as MDI adapters to fit the nozzle of MDI canister. This device generates 1-6 aerosol plumes. Numerous variations in the ID, shape, trajectory and location of the secondary cannulations and distal orifices in the wall of the ETT generate aerosol plumes with velocity, geometry, particle size and orientation that ensures effective aerosol delivery to the respiratory system.

REFERENCE TO THE RELATED APPLICATION

[0001] The present application incorporates by reference the copendingapplication entitled “ENDOTRACHEAL TUBE WITH AEROSOL DELIVERY APPARATUS”found by the same inventor of the present application and on the evendate here with and assigned serial number 10/072,282

BACKGROUND OF THE INVENTION

[0002] The present invention relates to medical-surgical devices forintubation i.e. endotracheal tube (ETT) intended for tracheal insertionin patients requiring mechanical ventilation. This tube is specificallydesigned for improved intrapulmonary deposition of aerosol particlesboth quantitatively as well as qualitatively in patients on mechanicalventilation via endotracheal tube. Multiple medications readily lendthemselves for pulmonary administration. Many diagnostic and therapeuticagents that can be utilized through this route are the bronchodilators,anti-inflammatory agents like steroids, antibiotics, anticholinergics,heparin, surfactant, antiproteases, gene transfer products, insulin,radioactive dyes, etc.

[0003] The advantages of intrapulmonary drug delivery as opposedsystemic administration are well known. The desired effect at the siteof local delivery as opposed to systemic administration minimizes sideeffects and is the preferred methodology for delivery of severalmedications. Conventional methods for aerosol delivery have resulted infailure of effective drug delivery to the lungs. They are limited notonly in total dose delivery but have also failed to achieve uniformintrapulmonary drug distribution. The two methods currently availablefor intrapulmonary drug delivery are highly inefficient. They are:

[0004] (I) Liquid bolus: The medication is instilled in the form ofliquid bolus via a bronchoscope or through an ETT. The distribution bythis method is non-uniform. Also there is a significant risk of inducingrespiratory distress and hypoxemia.

[0005] (II) Aerosol Inhalation: Conventional methods of aerosol drugdelivery have employed Metered Dose Inhalers (MDI's) with low boilingpoint propellants (CFC, HFA) or aerosol particles generated by heat,traditional compressed air nebulizers, or ultrasonic nebulizers. Eventhough these methods produce aerosol particles in respirable range (<5microns) compared with the liquid bolus medication, they are limited intotal dose delivery and lack uniform distribution of medication to thelungs. Only a small fraction of the medication reaches the lungs as themajority of the aerosol particles either adhere to the nasal passagesand oropharynx or are exhaled out. Efficiency of aerosol delivery dropseven further in patients who are intubated and require mechanicalventilation. Beck et al found that inhalation of nebulized materialthrough an endotracheal tube resulted in deposition of only 1.87% of thedelivered particles to the lungs. Methods employing a combinedventilator dispenser and adapter (U.S. Pat. No. 335,175) or other spacerdevices with MDI's have revealed equally poor results as most of theaerosol particles adhere to the ETT, the connectors and the inspiratorylimb of the corrugated plastic tube.

[0006] Investigators over the years have designed numerous endotrachealtubes in an attempt to overcome the hurdles associated with conventionalmethods of drug delivery to the respiratory system in patients onmechanical ventilation. Most designs of endotracheal tubes so far haveonly addressed the issue of drug delivery in the form of liquid bolus byincorporating drug irrigation devices in the traditional ETT in the formof secondary canalization with multiple micrometric openings (U.S. Pat.No. 5,146,936).

[0007] Factors that influence uniform delivery of aerosol particles inthe tracheobronchial tree are the mid-mean diameter of aerosol particles(which should be in the respirable range, i.e. <5 microns), velocity ofthe aerosol plume, geometry of the aerosol plume (narrow vs. wide), siteof the plume generation (proximal, distal or in the lumen of the ETT),orientation of the plume (central vs. eccentric), time of actuation ofMDI in the respiratory cycle, temperature and humidity in therespiratory circuit, etc. These features have not been addressed by anyof the currently available endotracheal tubes incorporating drugirrigation devices.

[0008] U.S. Pat. No. 4,584,998 to McGrail describes an ETT with up tothree secondary lumens in addition to the primary lumen in which onelumen can serve the purpose of delivering atomized gases to the patient.

[0009] U.S. Pat. No. 4,669,463 to McConnell shows ETT with a secondarylumen in the wall of the main lumen to deliver liquid medication to therespiratory system.

[0010] U.S. Pat. No. 4,821,714 to Smelser also describes an ETT with asecondary lumen to deliver medication to the respiratory system. Thesecond lumen splits into two branches that terminate as two orifices,one at the distal tip and other along the exterior wall of the ETT.

[0011] U.S. Pat. No. 5,504,224 to Anne M. Buret, Pam Jeblenski, andRobert A. Virag describe an ETT with a secondary lumen in the wall ofthe ETT that terminates at a perforation (Murphy eye). The single streamof medication splits when it Impacts on the distal edge of the openingresulting in delivery of medication both internally and externally ofthe ETT.

[0012] U.S. Pat. No. 5,642,730 to George Baran later continued as U.S.Pat. No. 6,079,413 assigned to the same inventor describes a cathetersystem for delivery of aerosolized medicine for use with pressurizedpropellant canister. The system includes an extension catheter that hasa length such that the proximal end is connected to the canister and thedistal end is positioned in the primary lumen or secondary lumen of theETT beyond its distal end in the respiratory system. The systemdescribes an extremely complex methodology for centering the device,attenuating the whipping effect and for preventing impaction losses,especially carinal impaction. Over and above this system is tooexpensive for clinical utility and is only being used as an experimentaltool in research laboratories.

[0013] U.S. Pat. No. 5,964,223 assigned to George Baran describes anebulizing catheter system similar to U.S. Pat. No. 5,642,730. Thissystem describes the flow of liquid medication through the lumen of acatheter which is nebulized at its tip by a flow of pressurized gasthrough a coaxial lumen.

[0014] U.S. Pat. Nos. 5,579,758, 5,594,987, 5,606,789, 5,513,630,5,542,412, 5,570,686 show a delivery device for intratrachealadministration of drug in aerosol form called ‘Penn CenturyIntratracheal Aerosolizer (Microsprayer)’ This device is not related toour field of invention i.e. medical surgical devices for intubation. Theclinical utility of this device in humans at this time is extremelylimited because of its high cost and need for sterilization after everyuse and as such it is solely being used as a research tool.

[0015] In summary, none of the prior art ETT's provide means foreffective local delivery of medication to the tracheobrochial tree ofboth lungs.

BRIEF SUMMARY OF THE INVENTION

[0016] The present invention relates to novel endotracheal tubes with animproved system of delivering aerosolized medication to patient'srespiratory system.

[0017] Objects of Invention

[0018] The main object of the present invention is to provide a modifiedETT that serves the following purposes:

[0019] Aerosol drug delivery to tracheobronchial tree.

[0020] Generation and delivery of aerosol particles at the distal end ofthe ETT with mid mean diameter that will allow uniform distributionthroughout the tracheobronchial tree.

[0021] Generation and delivery of aerosol particles at the distal end ofthe ETT such that a significant fraction of the aerosol particles reachthe tracheobronchial tree without adherence to the ETT.

[0022] Simple and inexpensive method of intrapulmonary drug delivery

[0023] To achieve all the objects without interfering with the primaryfunctions of the ETT. In other words, the improved system does notimpede intubation or in anyway make it more complicated for theoperator, or more traumatic to the patient.

[0024] The defined objects are obtained through our present inventioni.e. the ETT that incorporates several new features:

[0025] The new system uses a pressurized canister or a metered doseinhaler (MDI) to deliver aerosolized medication to respiratory system.MDI is a system that uses a pressurized canister that contains either asuspension of pulverized particles of medication in a liquid propellantor a solution of the medication in a liquid propellant. When thecanister is actuated, the mixture of medication and propellant isgenerated from the distal orifice or the nozzle of the canister.

[0026] In addition to the primary cannula for inflation of the distalballoon, the ETT has six additional secondary cannulations. Thesecondary cannulations originate in the proximal half of the ETT andcontinue distally within the wall of ETT in six different tracts toterminate as six pinhole orifices at the distal tip of the ETT. The sixorifices are arranged like the six edges of a hexagon, preferably be at1, 3, 5, 7, 9 and 11 o'clock positions (other arrangements are possibleas well). The secondary cannulations exit the ETT in its proximal halfand continue as six narrow tubular extensions outside the main frame ofthe ETT. The tubular extensions are preferably semi-flexible andterminate as six MDI adapters on the peripheral rim of the circularplate (again arranged like the six edges of a hexagon) or as cylindricalfittings for mating with MDI adapters. The terminal orifice of MDI ornozzle locks into the proximal port of MDI adapter. Actuation of MDIwith this assembly would deliver medication at the distal tip of ETT.

[0027] The six flexible tubules are further packaged in a single biggerhollow tube. The hollow tube along with six tubules terminate proximallyon the under surface of a circular plate. The distal end of the hollowtube terminates on the outer wall of the ETT, the junction where sixflexible tubules mate with six secondary cannulations. The circularplate has a connector in the center through which it attached to asecond circular plate. The lower circular plate is fixed to theconnector whereas the upper circular plate can freely rotate around thecentral connector. In the peripheral rim of the proximal circular plateis attached an MDI adapter. The MDI adapter tapers distally to terminateas an orifice that locks into the proximal orifice of the flexibletubule. The connector has a circular groove in the center and sixgrooves perpendicular to the circular groove equidistant from eachother. These perpendicular grooves are in alignment (parallel) with thecylindrical fittings for MDI adapters. The upper circular plate canrotate around the circumference of the circular groove as well as movesuperiorly and inferiorly along the six perpendicular grooves. Thisarrangement permits the MDI adapter to move superiorly along theperpendicular groove of the central connector, which unlocks the MDIadapter from the flexible tubule and positions it in the circulargroove. Rotation along the circular groove positions it in the nextperpendicular groove. On caudal movement of the circular plate the MDIadapter can now lock into the second flexible tubule. Hence, similarrepetitive movements would permit the MDI adapter to lock into sixflexible tubules one at a time in six different positions. Actuation ofthe MDI would generate aerosol particles that would be propelled throughthe MDI adapter into flexible tubules, secondary cannulations andfinally to be delivered at the terminal orifices at the tip of the ETT.The aerosolized particles generated at any given orifice will bepreferentially delivered to one lung. However, six different aerosolplumes generated from six orifices in different positions would ensure auniform distribution of aerosol particles to both lungs.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0028] Further features of the present invention will become apparent inthe accompanying drawings as well as the detailed description of thepreferred embodiments.

[0029]FIG. 1 is a plan view of the longitudinal length of ETT accordingto one embodiment of the present invention, incorporating the featuresdescribed in the summary of the invention.

[0030]FIG. 2 is a plan view of the longitudinal length of ETT accordingto an alternative embodiment of the present invention.

[0031]FIG. 3 is a plan view of the longitudinal length of ETT accordingto the most preferred embodiment of the present invention.

[0032]FIG. 4 is a plan view of the longitudinal length of ETT accordingto yet another alternative embodiment of the present invention.

[0033]FIGS. 5a, 5 b, 5 c, and 5 d are expanded cross-sectional views ofthe endotracheal tube according to the present invention taken alongsections LL1, LL2, LL3, LL4 of FIG. 1.

[0034]FIGS. 6a, 6 b, 6 c, 6 d are expanded cross-sectional views of theETT according to the present invention taken along sections LL5, LL6,LL7 and LL8 of FIG. 2.

[0035]FIGS. 7a, 7 b, 7 c, 7 d are expanded cross-sectional views of theETT according to the present invention taken along sections LL9, LL10,LL11 and LL12 of FIG. 3.

[0036]FIGS. 8a, 8 b, 8 c, 8 d are expanded cross-sectional views of theETT according to the present invention taken along sections LL13, LL14,L15, and LL16 of FIG. 4.

[0037]FIGS. 9a, 9 b, 9 c, 9 d are expanded cross-sectional views of theETT according to an alternative embodiment of the present inventiontaken along sections LL13 ,LL14, LL15 and LL16 of FIG. 4.

[0038]FIG. 10 is an expanded cross-sectional view of the bottom circularplate of the ETT described in FIG. 3.

[0039]FIG. 11 is a cross-sectional view of the bottom circular plate ofthe ETT described in FIG. 4.

[0040]FIG. 12 is a perspective view of the bottom circular plate of theETT described in FIG. 3.

[0041]FIG. 13 is a perspective view of the bottom circular plate of theETT described in FIG. 4.

[0042]FIG. 14 is a perspective view of the top circular plate of the ETTdescribed in FIGS. 1 and 2.

[0043]FIG. 15 is a perspective view of the top circular plate of the ETTdescribed in FIG. 3.

[0044]FIG. 16 is a perspective view of the top circular plate of the ETTdescribed in FIG. 4.

[0045]FIG. 17 is a cross-sectional view of the MDI adapter from above asdescribed in FIGS. 14, 15 and 16.

[0046]FIG. 18 is a cross-sectional view of the MDI adapter from below asdescribed in FIGS. 14 and 15.

[0047]FIG. 19 is a cross-sectional view of the adapter from the below asdescribed in FIG. 16.

[0048]FIG. 20 is a perspective view of the upper and lower platesaligned together as described in FIGS. 3, 10 and 15.

[0049]FIG. 21 is a perspective view of the upper and lower platesaligned together as described in FIGS. 4, 11 and 16.

[0050]FIG. 22 is a perspective view of an alternative embodiment of theupper and lower plates aligned together as described in FIG. 21.

[0051]FIG. 23 is a view from above of the direction of the aerosol plumegenerated from the ETT as described in FIG. 3.

[0052]FIG. 24 is a view from above of the direction of the aerosol plumegenerated from the ETT as described in FIG. 4.

[0053]FIG. 25 is a view from above of the direction of the aerosol plumegenerated from the ETT as described in FIG. 4 with an alternativeembodiment described in FIG. 9d.

DETAILED DESCRIPTION OF THE INVENTION

[0054] The present invention will now be described in detail byreference to the drawing figures, where as like parts as indicated bylike reference numerals.

[0055]FIG. 1 shows the first embodiment of the present invention. FIG. 1shows the longitudinal length of an ETT (1) which may be a conventionaladult or pediatric ETT. The ETT is an elongated hollow tube constructedfrom a plastic material (polymer) or silicone and is approximately 34 cmlong if an adult ETT and smaller if pediatric. The internal diameter ofthe tube can vary from 2.5 mm to 10 mm and the external diameter couldvary from 3.5 mm to 13 mm. The thickness of the wall of the tube couldvary from 0.5 mm to 2.0 mm. The tube is a flexible elongated conduitwith a concave surface on one side and a convex surface on the oppositeside. It's proximal end is connected to an adapter (2) which enables itto be connected to an elongated tube of a mechanical ventilator. Thedistal end has a 4 cm expandable cuff (3) starting approximately 4 cmfrom the distal tip and ending approximately 8 cm from the distal tip.In the distal 4 cm of the ETT, between the expandable cuff and thedistal tip of the ETT, there is a pair of oval holes (4) one each on theopposite surface of the tube facing each other. The size of the holescan vary between 5 mm and 1 cm. A small tube i.e. primary cannulation(5) of approximately 1 mm diameter runs within the wall on the convexside of the tube(s) and is connected to the expandable cuff forinflation and deflation by terminating on the outer surface of the ETtube as a 1 mm hole (7). This tube alternatively can be attached on theouter surface of the tube on the convex side. The primary cannula has aproximal flexible part (8) which continues outside the main tubularstructure of the ETT (1). The flexible part starts at approximately 18cm from the distal tip of the ETT and continues proximally for a fewcentimeters to terminate into a cuff inflation indicator (9) and adapter(10) for a syringe. The connection between the flexible and rigid partof the primary cannula is through an opening on the outer surface of theETT (6) which is also 1 mm in ID. On the lateral surface of the ETTstarting at the same level as the cannulation for the inflation of theballoon (6) or at a higher level (13) there originates another secondarycannula (11) on the outer surface of the ETT that continues within thewall of the ETT. The ID of this secondary cannulation can vary from 0.01mm to 1.25 mm in size. This secondary cannulation continues distallybeyond the balloon to terminate as a pinhole opening (12) at the distaltip of the ETT. The course of the secondary cannulation within the wallof ETT may be variable and as demonstrated in this figure, it is fromthe outer surface to the inner surface to terminate at the distal tip ofthe ETT. The secondary cannulation is an extension of a semi-flexibleproximal cannula (14) which is on the outside of the main tubularstructure of the ETT (1) without adhering to it just like the flexiblepart of the primary cannula (8). The semi-flexible cannula (14) makes aconnection with the secondary cannulation (11) through an opening (13)on the outer surface of the ETT. The proximal end of the flexiblecannula terminates into a metered dose inhaler (MDI) adapter (15); Theflexible cannula maybe an extension of MDI adapter or the two may befused together if made of different materials. The proximal port of theMDI adapter is designed to fit the nozzle of MDI canister. The distalend of the adapter tapers into a cylindrical tube matable to theflexible canula, the two made of different polymers. This assemblyenables aerosolized medication from MDI canister to be delivered at thedistal tip of the ETT on actuation of the canister. The device mayinclude a special syringe, the terminal injection port of which may havea configuration identical to the nozzle of MDI. This would enable theMDI port to be used for delivering any liquid medication to therespiratory system via a manually operated syringe or any pressurizedsource. The port may include a cap for closure when not in use.

[0056]FIG. 2 shows the longitudinal view of the ETT (16) associated withalternative embodiments of secondary cannulation. The primarycannulation (18) runs on the convex wall of the ETT to terminate as anorifice (19) on the outer surface. This ETT incorporates two secondarycannulations (23 and 28) as opposed to one shown in FIG. 1. The twopoints of origin of the secondary cannulations (22 and 27) asdemonstrated in FIG. 2. The secondary cannulations may or may not havesimilar tracts. They are located on the opposite lateral surfaces of theETT and continue distally to terminate as two pinhole orifices (24 and29) at the distal tip of the ETT. The secondary cannulations (23 and 28)are extensions of a semi-flexible proximal tubules (21 and 26)respectively. The flexible tubules are either extensions of the MDIadapters or matable with it as shown in FIG. 1. Also the length of theflexible tubule outside the main tubular structure of ETT could bealtered as can the length of secondary cannulations in the wall of theETT.

[0057] There are numerous varieties of plastic materials that may beused to manufacture the endotracheal tubes (ETT's); some examples of thesame may be—thermoplastics (polyvinyl chloride, polyethylene,polypropylene) silicone, teflon, et; though the one that is mostcommonly use is polyvinyl chloride (PVC). Since the differences in thecompliance and coefficient of friction of various materials couldinfluence the delivery of aerosol medication, the secondary cannulationcould be coextruded using a compound or a polymer different from the oneused to manufacture the primary ETT. The coextrusion may optimize thephysical properties of the secondary lumen and maximize aerosoldelivery. Examples of some coextrusions may be—PVC and teflon, PVC andpolypropylene, PVC and silicone, PVC and polyethylene, etc. ETT may bedisposable or reusable after sterilization.

[0058]FIG. 3 is the plan view of the most preferred embodiment of ourpresent invention. The detailed description of FIG. 3 and the rationalefor this embodiment of ETT will become obvious with the explanationoutlined below.

PARTICLE SIZE, PLUME CHARACTERISTICS AND DRUG DELIVERY

[0059] Effective drug delivery is closely related to particle size.Larger particles may provide a greater total drug deliver; however, auniform distribution of medication in the distal tracheobronchial treerequires particle size distribution in the respirable range (<5microns). Besides particle size, the drug delivery rate and distributionis also a function of the site if aerosol particle generation and thecharacteristics of the aerosol plume. Even though the size of aerosolparticles generated in case of a suspension of pulverized powdermedication in a liquid propellant is predetermined and is a function ofthe size of the crushed solid particles of powder medication, the drugdelivery rate and distribution will be tremendously affected by thefeatures of secondary cannulation and the terminal orifice at its' tip.The critical features of secondary cannulations are its length, ID,shape and orientation/trajectory. The features of the distal orifice areits' location, orientation, shape, and ID. All the aforementionedfeatures will also influence the plume geometry, velocity andorientation and hence the distribution of the particles in the distaltracheolbronchial tree.

[0060] In our invention, the ID of the secondary cannulation may beuniform throughout or tapered along the entire length. Alternatively, itmay be uniform in the proximal part and tapered near the distal part.The ID of the secondary lumen may vary from 0.01 mm to 1.25 mm. Thecombined length of the secondary cannulation within the wall of the ETTand its proximal flexible part may also play a critical role in thetotal drug delivery. A narrow ID of the secondary cannulation is veryimportant for the aerosol medication to reach the distal tip of thesecondary cannulation over approximately 25-30 cm of length; however, ifthe ID is too narrow, it may pose resistance to the flow and impedeaerosol delivery. Another very important factor is the course(trajectory) of the secondary lumen in the wall of the ETT. Thetrajectory may be directed from the outer wall to the inner wall;alternatively the secondary lumen may stay closer to the outer wallthroughout; it may stay closer to the inner wall throughout; or it maystay closer to the outer wall for the most part and may be redirected tothe inner wall near the distal part of the ETT. A change in the plane ofthe secondary cannulation in the distal part of the ETT (range 1 mm-10mm) will change the orientation of the secondary lumen by approximately5 to 45 degrees. The preferable change in the angle, however, may be10-15 degrees only in order to prevent tracheal or carinal impactionlosses. In another modification of our invention, the secondarycannulation can run inside the primary lumen on the inner wall of theETT or it could run on the surface on the outer wall of ETT.

[0061] The features of the distal orifice in our invention may also havenumerous variations. The distal orifice of the secondary cannulation islocated at the tip of the ETT, preferably not in communication with theprimary lumen at the ETT and not protruding beyond the distal tip of theETT. The shape of the distal orifice is preferably circular, however,the shape may be semi circular, lunar, etc. The ID of the distalorifice, which may vary from 0.01 mm to 1.25 mm, may be the same ordifferent from the ID of the secondary cannulation. The ID of the distalorifice may be made extremely small to generate a narrow plume or theterminal orifice may be made larger than the secondary cannulation withsplaying in order to generate a wider plume. The location of the orificemay be closer to the inner wall or outer wall or it may be in the centerof the ETT's wall.

[0062] An aerosol plume which is central, and wide will result in agreater fraction of the drug loss due to impaction on the ETT (ifgenerated proximal to the ETT or in the lumen of the ETT) or the wall ofthe trachea (if generated distal to the ETT) prior to reaching thedistal tracheobronchial tree. An aerosol plume that is central, narrowand fast is likely to lose a greater portion of the medication bycarinal impaction. An eccentrically located narrow and fast plume willavoid carinal as well as tracheal impaction losses and will ensureaerosol particle delivery to the proximal tracheobronchial tree. Thedistal tracheobronchial tree delivery may require an eccentric, narrowand slower plume or an eccentric wide and fast plume.

[0063] In our invention the distal orifice of the secondary cannulationis located at the tip of the ETT and generates aerosol at a location inthe tracheobronchial tree beyond the ETT, thus avoiding impactionlosses. The velocity and width of the plume could be altered byadjusting the shape and ID of the secondary cannulation and the distalorifice. Over and above the orientation of the plume can be influencedby the trajectory of the secondary cannulation. In our invention, sincethe trajectory is from the outer wall towards the inner wall, preferablyin the distal part of the secondary cannulation, the plume will beoriented away from the tracheal wall. The eccentric location of theorifice in the wall of the ETT in our invention is preferable as itprevents carinal and tracheal impaction losses. The diameter of the ETTis far smaller than that of the airway passages i.e. the trachea. Onplacement of the ETT in the trachea and inflating the distal balloon,the wall of the distal circular edge of the ETT is a few millimetersaway from the tracheal wall and hence the orifice located in the wall ofthe distal tip of ETT. Depending on the size of the ETT the two lateralterminal orifices os secondary cannulations may be located approximatelyin the center between the carina and the left or right mainstem bronchi.

[0064] One may argue that the lateral location of the orifice woulddirect the plume preferentially to one lung. This actually may be oftremendous benefit if one wants preferential delivery of medication toone lung which has the pathology. However, if the pathological conditionaffects both the lungs uniformly the problem can be completely obviatedby having two distal orifices diametrically opposite to each other onthe lateral surface of the ETT as described in the second embodiment ofour invention in FIG. 2. It is also quite conceivable that at the timeof placement of the ETT and inflation of the balloon, the ETT may getslightly rotated so that the two lateral orifices may not end up beingin the preferred 3 o'clock and 9 o'clock positions. This problem ofmalaligment of the two lateral orifices with respect to the carina andthe right and/or left mainstem bronchi can be overcome by the mostpreferable embodiment of our invention as described in FIG. 3.

[0065]FIG. 3 shows the longitudinal view of the ETT (30) associated withan alternative embodiment of secondary cannulation. FIG. 3 demonstratesthe most preferred embodiment of our invention with six secondarycannulations in the wall of ETT terminating in six distal orificeslocated on the circular edge of the distal tip of ETT. The six orificesmay preferably be equidistant from each other like the six edges of ahexagon at 1, 3, 5, 7, 9 and 11 o'clock positions. However, the sixorifices may have several alternative symmetric or asymmetricarrangement. The six secondary cannulations and their distal orificesmay be identical or completely different from each other in shape, ID,trajectory, and orientation. Such an arrangement would generate plumeswith different characteristics i.e. geometry, velocity and orientation.In this respect a preferable arrangement would be to have three orificeson each lateral surface of ETT with the ability to generate narrow andfast, narrow and slow, and wide and fast plumes from the three orificeson each side. In another arrangement, there could be eight secondarycannulations and orifices, four each on the two lateral surfaces inorder to generate the wide and slow eccentric plume as well. Thisarrangement with total eight plumes (¾ plumes with differentcharacteristics and orientation on each lateral surface) will ensure auniform and effective distribution of aerosol particles to proximal anddistal tracheobronchial tree of both lungs.

[0066]FIG. 3 shows the longitudinal view of the ETT (30), an adapter atits proximal end (31) and an inflation cuff (37). The primary cannula(35) has a flexible portion (33), the point of origin of the primarycannula (34), distal orifice (36) and proximal cuff inflation indicatingan adapter for syringe (32). There are six secondary cannulations in thewall of the ETT. They originate on the outer surface of the ETT at thesame level (34) or a level higher (35) than the primary cannula. The sixcannulations continue distally in the wall of the ETT to terminate assix orifices, as described before, at the distal tip of the ETT. Two outof six secondary carmulations (48 and 49) and a single distal orifice(47) of the secondary cannulation (49) are demonstrated in FIG. 3. Thesecondary cannulation continue proximally as six semiflexible tubules(45) outside the main tubular structure of the ETT(30) without adheringto it just like the flexible part (33) of primary cannulation. The sixflexible tubules are packaged in a larger hollow tube (43) thatterminates distally on the outer wall of the ETT. This arrangementhowever may be changed and there could be two larger hollow tubespackaging three flexible tubules on each side. The proximal end of thehollow tube (43) and the six tubules (45) terminate on the under surfaceof a circular plate (42). The six flexible tubules (45) terminate as sixMDI adapters, or alternatively, the six tubules terminate as six rigidcylindrical tubules for mating with MDI adapters on the ventral surfaceof the circular plate (42). The circular plate (42) is attached toanother circular plate through a central connector (40). The centralconnector (42) has a circular groove in the center and six groovesperpendicular to the circular grooves that are in alignment (parallel)with the six MDI adapters. The lower circular plate (42) is fixed to thecentral connector (40) whereas the upper circular plate (39) can rotatearound the circular groove as well as move up and down along theperpendicular grooves of the central connector with the help of a handle(41). Located on the peripheral rim of the ventral surface of the upperplate (39) is an MDI adapter (38). The nozzle of a pressurized canisterfits into the proximal port of MDI adapter (38). The MDI adapter tapersdistally to terminate on the under surface of the upper circular plate(39). The MDI adapter (38) locks into one of the rigid cylindricaltubules, the proximal end of the flexible tubules (45), located on thedorsal surface of the lower plate. The upper circular plate (39) canrotate in the circular groove, move superiorly along the perpendiculargroove (to unlock) and move inferiorly along the perpendicular groove(to lock) the MDI adapter into six rigid cylindrical tubules one at atime in six different positions. Hence, actuation of MDI in differentpositions would result in generation of six aerosol plumes at the distalorifices (47) of the secondary cannulations (49).

[0067]FIG. 4 shows an alternative embodiment of our invention to furtherobviate the tracheal deposition of aerosol particles as well as alterthe aerosol particle size. FIG. 4, which shows the longitudinal view ofETT (50), is identical to the ETT described in FIG. 3 but with twoalternative embodiments. The six flexible tubules (65), and the sixsecondary cannulations (67) in the wall of the ETT have two coaxiallumens. The secondary cannulations terminate as two coaxial orifices(68) at the distal tip of the ETT (50). The flexible cannulations (65)are packaged in a hollow tube (63), the proximal end of which terminateson the dorsal end of the lower circular plate (62) along with theflexible tubules. The distal end terminates on the outer wall of the ETT(64). The point of entry or fusion with secondary cannulations (66) ofthe six flexible tubules (65) on the wall of the ETT is demonstrated.The primary cannulations (54) with all the associated features—distaltip (55), inflatable cuff (56), flexible cannula (52), entry point (53)and cuff inflation indicator and adapter (51) are also demonstrated inFIG. 4.

[0068] The second alternative embodiment is a modified MDI adapter (57)with an additional side port (58). The upper circular plate (59) with ahandle (60) along with the central connector (61) are demonstrated. TheMDI adapter has two ports. The main port (57) that has a proximal portto fit the nozzle of the pressurized canister and a distal orifice thatmakes an airtight connection with the inner coaxial lumen of the rigidcylindrical tubule. It also has a side port (58) that communicates withthe outer coaxial lumen of the rigid cylindrical tubule. Note that therigid cylindrical tubule is the proximal end of the flexible tubule formating with MDI adapter. The inner lumen of the main port of MDI adapterserves to generate aerosol particles by MDI canister or deliver liquidmedication via a syringe at the distal tip of the ETT. The side port orthe outer lumen of MDI adapter may be used for vapor or gas flow foreither anesthesia or to disperse the aerosolized particles generatednear the distal tip of ETT away from the trachea as well as to break theparticle into smaller size. This device, just like the one described inFIG. 3, incorporates the special feature of MDI adapter's ability torotate and lock in six different positions, such that through the innercoaxial lumen liquid medication or aerosol spray is conveyed and thepressurized gas is conveyed in the annular region between the inner andthe outer tubular membranes. This coaxial airflow may direct the plumeaway from the tracheal wall and carina and hence prevent impactionlosses.

[0069] A variety of drug delivery rates and particle size distributioncan be achieved by altering the coaxial orifice, diameters, pressure andflow characteristics of the liquid and gas in the respective orificesand by adjusting the distance between the liquid and gas flow byaltering the thickness of the membrane separating the two lumens. Theliquid lumen, the gas lumen and the thickness of the wall separating thetwo lumens may vary from 0.025 mm to 1 mm.

[0070] In another alternative embodiment of our invention, as describedin FIG. 3, there is only one circular plate without a central connectoror the upper circular plate. The six flexible tubules terminate into thesingle circular plate as six MDI adapters on the ventral surface of theplate. They may appear just like the MDI adapter demonstrated in FIG. 1.The nozzle of the MDI canister can fit into the proximal ports of MDIadapters one at a time in six different positions by manual operation.The circular plate may have a cap to cover MDI adapters when not in use.

[0071] In another alternative embodiment of our invention as describedin FIG. 4, the inner coaxial lumen of the six flexible tubules mayterminate on the ventral surface of the circular plate as MDI adaptersand the outer coaxial lumen of the flexible tubules may terminate as sixside ports on the outer surface of the circular edge of the single. Inanother alternative embodiment of our invention, the coaxial arrangementmay be uniform and cylindrical for the most part but the inner and/orouter lumen may become semicircular in the terminal part of the ETT. Theflow of gas and liquid aerosol in this arrangement would direct theaerosol plume further away from the tracheal wall. In yet anotheralternative embodiment of our invention, the inner lumen may terminatejust proximal to the distal tip of the outer semicircular lumen.

[0072]FIG. 5a is a cross section at level LL1, which shows a hollow tube(72), the wall of the tube (71), the inner surface of the wall (73), andthe outer surface of the wall (74).

[0073]FIG. 5b is the same as FIG. 5a but with the appearance of anadditional secondary cannulation (79) starting close to the outer wall(78). The main wall (75), the inner wall (77), and the lumen (76) aredemonstrated.

[0074]FIG. 5c is the cross section at the level LL3. This is the same asFIG. 5b, but there may be a change in the position of the secondarycannulation which may stay near the outer wall, move closer to thecenter move closer to the inner wall of the ETT. There is an additionalprimary cannula (85) on the convex side of the ETT near the outer wallfor inflation and deflation of the balloon cuff.

[0075]FIG. 5d is the same as FIG. 5c but with the absence of primarycannula (85) as it terminates at a higher level near the expandableballoon. The secondary cannula (90) may be closer to the inner wall(88).

[0076]FIG. 6a is the same as FIG. 5a.

[0077]FIG. 6b is the same as FIG. 5b but with the two secondarycannulations (105 and 106) on lateral surface of the ETT diametricallyopposite to each other.

[0078]FIG. 6c is the same as FIG. 6b but with an additional primarycannulation (107).

[0079]FIG. 6d is the same as FIG. 6c but two secondary cannulations (112and 113) on the lateral surface near the inner wall of the ETT but withloss of primary cannulation (107).

[0080]FIGS. 7a, 7 b, 7 c, and 7 d show the details of four crosssections at four levels, LL9-12 of the ETT as shown in FIG. 3.

[0081]FIG. 7a is the same as FIG. 6a.

[0082]FIG. 7b demonstrates the main lumen (119), the wall of the ETT(118), the inner wall (120), the outer wall (121).

[0083] There is appearance of six secondary cannulations (22) whichenter the ETT approximately at the same level but follow differenttracts in the wall of the ETT.

[0084]FIG. 7c is the same as FIG. 7b but with an additional primarycannula (126). The six secondary cannulations (127) however are mostseparated as they follow different tracts within the wall of the ETT.

[0085]FIG. 7d is the same as FIG. 7c but with disappearance of primarycannula (128). The six secondary cannulations (123) now appear as thesix edges of a hexagon on the distal tip close to the inner wall of theETT. The six distal orifices may not be equidistant from each other andmay be have alternative arrangement along the circular edge of the tipof the ETT.

[0086]FIGS. 8a, 8 b, 8 c, and 8 d show details of four cross sections atfour levels LL13-LL16 with an alternative embodiment as shown in FIG. 4.

[0087]FIGS. 8a, 8 b, 8 c, and 8 d are the same as FIGS. 7a, 7 b, 7 c,and 7 d respectively; the only difference that is shown here is withrespect to the secondary cannulations which have two coaxial lumens asopposed to a single lumen as shown in FIG. 7.

[0088]FIGS. 9a, 9 b, 9 c, and 9 d represent another alternativeembodiment of the four cross sections at levels LL13-LL16 asdemonstrated in FIG. 4.

[0089]FIGS. 9a, 9 b, and 9 c are identical to FIGS. 8a, 8 b, and 8 c.

[0090]FIG. 9d is the same as FIG. 8d except for a single modification.The two coaxial secondary cannulations in 9 d are different from theones in FIG. 8d. FIG. 9d has circular inner lumen just as demonstratedin FIG. 8d but the outer coaxial lumen is semi-circular as opposed tocircular as demonstrated in FIG. 8d. Alternatively, in anotherembodiment both inner and outer lumen in 9 d could be semi-circular withthe circular edges on the opposite lateral sides.

[0091]FIG. 10 shows details of a cross sectional view of the lowercircular late (179), the six flexible tubules, three of which have beendemonstrated by arrows (180,181, and 182) that terminate on the ventralsurface of the peripheral rim (178) of the circular plate (179) like thesix edges of a hexagon. The central connector (184) along with thecentral attachment are also demonstrated here.

[0092]FIG. 11 shows the details of the cross sectional view of anotherembodiment of the lower circular plate that corresponds to FIG. 4. Thisis the same as FIG. 10, but with a single modification—the six tubuleshave two coaxial lumens, the inner one (191) for the liquid medicationor liquid aerosol, and the outer one (190) for the gas or vapour flow.The circular plate (186), the flexible tubules (187,188, and 189), theperipheral rim (185) of circular plate, the central connector (193), andthe central attachment of the plate to the rod (192) are demonstrated.

[0093]FIG. 12 is a perspective view of the lower circular plate (195)shown in FIG. 10. The flexible tubule (196) terminates (195) as rigidcylindrical tubule on the ventral surface of the peripheral rim (194) ofthe circular plate (195). Other flexible tubules (196 and 197) aredemonstrated as well.

[0094]FIG. 13 is a perspective view of the lower circular plate (200)shown in FIG. 11. The two coaxial tubules—inner (205) and outer (204)terminate on the ventral surface (203) of the circular plate.

[0095]FIG. 14 shows MDI adapter (208) as shown in FIGS. 1 and 2. The MDIadapter is located in the center at the circular plate (209) withperipheral handles (210 and 211). The MDI adapter tapers distally tocontinue as a single flexible tubule (212) that continues as secondarycannulation (not shown) in the wall of the ETT.

[0096]FIG. 15 shows the upper plate with MDI adapter (211)as shown inFIG. 3. A single MDI adapter (211) on the peripheral rim (212) of thecircular plate is demonstrated here. The circular plate rotates around acentral connector (215) in the central groove (213). To facilitate therotation, the central plate has a handle (214).

[0097]FIG. 16 shows upper plate (220) with MDI adapter (217) with ahandle (221), a central connector and attachment (222) as shown in FIG.4. A single MDI adapter (217) with a side port (218) is attached to thecircular plate (220) at its peripheral rim (219).

[0098]FIG. 17 shows the top cross sectional view of MDI adapter shown inFIGS. 14, 15, and 16. The MDI adapter has an inlet port (226) and twoconcentric rings (225 and 226) with decreasing circumferencial perimetersuch that the MDI nozzle locks into the innermost concentric ring (226).The terminal orifice (227) marks the point of fusion or mating with theproximal end of the flexible tubule. The structure of the internal lumenof MDI adapter could be modified in numerous ways to fit the nozzle ofthe MDI.

[0099]FIG. 18 shows the bottom cross sectional view of the MDI adaptershown in FIGS. 14 and 15. The MDI adapter's innermost ring (229) to fitthe nozzle of MDI and the distal orifice (228) through which the aerosolparticles are generated are demonstrated in this figure.

[0100]FIG. 19 shows the bottom cross sectional view of the MDI adaptershown in FIG. 16. It is the same as FIG. 18 except for one extra outerring (230). The shaded area (233) between the two rings (230 and 232) isa tubular hollow space that communicates with a side port (218) shown inFIG. 16. This hollow space is the coaxial outer lumen.

[0101]FIG. 20 shows the upper and the lower plates together as shown inFIGS. 3, 12 and 15.

[0102]FIG. 21 shows the upper and the lower plates together as shown inFIGS. 4, 13 and 16.

[0103]FIG. 22 demonstrates an alternative embodiment of FIG. 21 with theupper and lower plates aligned together. As opposed to the MDI adapter(258) having a side port for the gas flow, the side port could be a partof the assembly of the lower plate (267). The central flexible tubule(266) terminates proximally on the ventral surface (265) of the lowerplate (264). The side port (267) terminates proximally (268) on thedorsal surface of the lower plate. Distally the side port continues asthe outer coaxial flexible tubule (269). The MDI adapter (258) of theupper plate (259) locks into the proximal orifice (265) of the flexibletubule. The MDI adapter can lock in six different positions one at atime with each of the flexible tubules as described earlier. The sideport (267) serves the purpose of gas or vapor flow to the outer coaxiallumen.

[0104]FIG. 23 shows the cross sectional view of the ETT as shown in FIG.7d along with two dimensional geometry and direction of the plumegenerated from each of the orifices of secondary cannulations at thedistal tip of the ETT. The terminal orifice generates a plume that movesdistally along the inner circular edge of the ETT (arrows 274 and 277)as well as away from the inner edge (arrow 276). The area under thecurve of the aerosol plume generated from any one orifice maybeapproximately ⅓ to ½ of the area formed by the primary lumen at theendotracheal tube. The six aerosol plumes generated from six distalorifices ensure uniform distribution of medication in thetracheobroncial tree of both lungs as demonstrated.

[0105]FIG. 24 is the same as FIG. 8d with the direction of the plumes asshown in FIG. 23. The airflow in the outer coaxial tube will prevent thetracheal and carnal impaction of aerosol particles.

[0106]FIG. 25 is the same as FIG. 9d with the direction of the plumebeing further away from the tracheal wall (293). In this figure theairflow from the semi-circular outer coaxial tube (295) will redirectthe liquid aerosol from the inner lumen (294) away from the trachealwall.

[0107] It is noted that the illustration (drawings) and description ofthe preferred embodiments have been provided merely for the purpose ofexplanation and although the invention has been described herein withreference to particular means, materials and embodiments, the inventionis not intended to be limited to the particulars disclosed herein;rather the invention intends to all functionally equivalent structures,methods and uses such as are within the scope of the appended claims.

What is claimed is:
 1. An improved method of drug delivery to patient'srespiratory system comprising: an endotrcheal tube (ETT) having a maintube with provision for a connector at the proximal end; the saidconnector may be connected to a ventilator, ambu bag, T-piece or anybreathing apparatus or gas source (gas cylinder or wall source); a mainlumen extending through the main tube; a wall surrounding the mainlumen; the said tube with or without an expandable balloon cuff at thedistal end; a primary cannulation formed in the wall of the ETT forinflation and deflation of the balloon cuff with a coupling adapted toconnect to a syringe; an ETT with secondary cannulation/cannulations (1to 6 or more) in its' wall; the said cannulation(s) terminating with aorifice at the distal tip of ETT; the said cannulation's distal orificepreferably not in communication with the main lumen of the ETT; the saiddistal orifice of the secondary cannulation not extending beyond themain tip of the ETT; the said cannulation with a proximal exit port onthe outer wall of the ETT; the said exit port makes a connection with asemi-flexible tubule outside the main structure of the ETT; the saidflexible tubule terminating at the proximal end as MDI adapter or rigidcylindrical tubule that fuses or mates with MDI adapter; the said MDIadapter with a provision for fitting the nozzle of MDI canister; an ETTwith six or more orifices at the distal tip which may or may not beequidistant from each other, preferably in 1, 3, 5, 7, 9, 11 o'clockpositions, but may have an alternative arrangement anywhere along thecircular distal edge of the ETT; a pressurized canister that contains asuspension of pulverized medication in a liquid propellant (for exampleCFC) or a solution of medication in a liquid propellant (for exampleHFA); the said canister with a nozzle; the aerosol particles ofmedication and liquid propellant exiting from the said nozzle onactuation of the canister; the propellant evaporating and the saidmedication particles delivered to the respiratory sytem; the saidpressurized canister, the time of actuation of which can be varied withinspiratory and/or expiratory phase of respiratory cycle of a patientwho is breathing spontaneously or mechanically through a ventilator; thesaid “medication” or “drug” should be considered to include anysubstance or agent that can be delivered to the tracheobronchialtree/respiratory system for diagnostic or therapeutic purposes in theform of solid, liquid or gas; an ETT, the wall of which may be ofvariable thickness, durometer, flexibility, lumen ID, lumen OD, terminalend (curved or straight), curvature (convexity/concavity), secondaryorifices (Murphy's eye 1 or 2), and lumen shape (round or oval); an ETTwith provision for the flow of humidified or non-humidified air atcontrolled temperature to the patient's respiratory system; an ETT suchthat 1 to 6 (or more) aerosol plumes can be generated at its distal tipto deliver aerosol medication to each lung individually (via a singleport) as well as a uniform distribution to both lungs via multipleports; an ETT with multiple secondary carmulations and terminal orificeswhich may be identical or different from each other in shapes, ID's,trajectories and orientations to generate multiple same or differentaerosol plumes having velocity, geometry, orientation and particle sizesin order to maximize uniform drug delivery to tracheobronchial tree ofboth lungs; the said plumes may be eccentric, narrow and fast;eccentric, narrow and slow; eccentric, wide and slow; eccentric, wideand fast; intubating the patient with the said ETT;
 2. The method ofclaim 1 further comprising: the secondary cannulation in the wall of theETT; the said secondary cannulation in the same plane throughout itscourse in the wall of the ETT or with a change in the plane in itscourse; the said cannulation with course (tract) near the inner wallthroughout; or near the outer wall throughout; or partly near the outerwall and partly near the inner wall in a variable ratio; the saidcannulation may be on the outer surface of the wall of the ETT; the saidcannulation may be on the inner surface of the wall of the ETT withinthe main lumen of the ETT; the said cannulation with the point of exiton the outer surface of the wall of the ETT at a level higher or lowerthan the point of entry of the primary cannulation; the said cannulationwith tracts which may be straight, curvilinear, spiral or have any othertrajectory or combinations of the same; the said cannulation with itsdistal tip splitting into greater than one tubules within the wall ofthe ETT to terminate as multiple orifices in the distal tip of the ETT.the secondary cannulation with variations in the ID; the saidcannulation may be uniform throughout the entire length or taperedthroughout the entire length or both uniform and tapered in a variableratio in the proximal and/or distal parts of ETT; the secondarycannulations with variable shapes; the said cannulation preferablycylindrical but may be of alternative shapes; the said cannulation witha proximal cylindrical part that may become splayed, horn-shaped or analternative shape at the distal end to generate slower and wider plume;the secondary cannulations may be manufactured of the same material asthe main ETT or coextruded with a material different from the one usedto manufacture the main ETT; the said coextrusion done to change thephysical properties of the lumen of the secondary cannulations; the saidcoextrusion facilitating maximum aerosol drug delivery to thetracheobronchial tree;
 3. Methods of claim 1 further comprising:terminal orifice(s) at the tip of the ETT; the said orifice maybe ofdifferent ID's (same, smaller or larger than secondary cannulations);different geometrical shapes (circular, semi-circular, lunar etc.);different locations (near the outer wall, inner wall, center, on theouter surface of the ETT, or on the inner surface of the ETT)
 4. Themethods of claim 1 further comprising: the flexible tubule(s)(preferably 1 to 6 but could be more); the said tubules packaged in alarger hollow tube; the said tubules with variable length, flexibility,ID, OD, thickness, durometer, and shape; the said tubules terminating asMDI adapters or mating with MDI adapters at the proximal end; theproximal end of the said tubules terminating on the ventral surface of acircular plate in the center of the plate (if single)and at theperipheral rim of the plate (if multiple);
 5. The method of claim 1further comprising: two circular plates; the said plates attachedthrough a central connector; the lower plate preferably fixed; the upperplate which can rotate in a circular fashion or up and down along thecircular and perpendicular grooves of the central connector; theassembly permitting fusion or mating of the proximal end of flexibletubules on the lower circular plate with the distal end of MDI adapteron the upper plate in six (or more) different positions; the saidarrangement permitting flow of aerosol medication from MDI to the distaltip of the ETT via MDI adapter, flexible tubule and secondarycannulation; a singular circular plate with flexible tubules terminatingas MDI adapters on the peripheral rim of the plate; the nozzle of MDIfitting into the said six MDI adapters one at a time in six differentpositions by manually moving the MDI canister;
 6. The method of claims1-5 with an improved system on delivery of medication to patient'srespiratory system comprising: an ETT with MDI adapter, flexibletubules, secondary cannulation, and distal orifices with two coaxiallumens; the said inner and outer coaxial lumens with variable ID's,OD's, shapes, lengths, trajectories, orientation, thickness of theirwalls and distance from each other; the said coaxial lumens may becoextruded with different materials; the said inner lumen for liquid orliquid aerosol flow and the said outer lumen for gas or vapor flow; 7.The method of claims 1-6 with an improved system of delivery of aerosolmedication to both lungs comprising: a suction catheter incorporatingall the principles of our device to serve dual purpose; a suctioncatheter that can be inserted through the ventilator lumen of ETT; thesaid catheter can aspirate respiratory secretions and then delivermultiple aerosol plumes (1 to 6 or more) via multiple orifices in thedistal tip of the said catheter; the said catheter may be disposable orretained in a sterile sheet connected to the proximal end of the ETT sothat it could be reinserted.